<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd"> 
<html xmlns="http://www.w3.org/1999/xhtml"> 
<head> 
    <meta http-equiv="Content-Type" content="text/html; charset=utf-8" /> 
    <title>如何使用js</title>
</head> 
<body>    
    <!-- <button style="background: orange;" onclick="alert(1)">弹出1</button>     -->
    <div>星星课堂</div>
    <script>
        alert(123)
    </script>
</body> 
</html>